1. Technical Field
Example embodiments relate to a method of forming a phase change layer and a method of manufacturing a storage node having the phase change layer.
2. Description of the Related Art
The resistance of a phase change material may vary depending to whether the phase change material is in a crystalline state or in an amorphous state. Additionally, the phase change material may change from a crystalline state to an amorphous state, and vice versa, depending on temperature. A phase change memory device may include a phase change layer made of the above-described phase change material as a means for storing bit data. An example of a phase change memory device may include a PRAM (phase change random access memory), and an example of a phase change material may include Ge2Sb2Te5 (GST). A GST layer may be formed using a physical vapor deposition (PVD) method. However, controlling the growth of the GST layer may be difficult when using a PVD method. Additionally, deposition speed may be relatively low, and the density of the GST layer may be decreased. Accordingly, a metal organic chemical vapor deposition (MOCVD) method or a cyclic chemical vapor deposition cyclic-CVD) method may be used to obtain an improved GST layer.
A conventional method of forming a GST layer using a conventional CVD method will be briefly described. A substrate, including a layer on which a GST layer is to be formed, may be loaded into a CVD chamber. The substrate may be heated to the appropriate temperature for deposition. Precursors, including metal elements forming the GST layer, may be supplied simultaneously through a shower head to the heated substrate. For example, suitable precursors may be organic metal compounds including germanium (Ge), antimony (Sb), and/or tellurium (Te). As the substrate is heated to the appropriate temperature for deposition, the precursors may decompose and be absorbed onto the layer as a result of the reaction of metallic elements of the precursors with the layer. The precursors not reacted or absorbed onto the layer may be discharged from the CVD chamber.